20832257 has 4 divisors (see below), whose sum is σ = 20842416. Its totient is φ = 20822100.

The previous prime is 20832239. The next prime is 20832263. The reversal of 20832257 is 75223802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 75223802 = 2 ⋅37611901.

It is a cyclic number.

It is not a de Polignac number, because 20832257 - 2⁶ = 20832193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20832277) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 803 + ... + 6504.

It is an arithmetic number, because the mean of its divisors is an integer number (5210604).

It is a Proth number, since it is equal to 2543 ⋅ 2¹³ + 1 and 2543 < 2¹³.

Almost surely, 2^20832257 is an apocalyptic number.

It is an amenable number.

20832257 is a deficient number, since it is larger than the sum of its proper divisors (10159).

20832257 is an equidigital number, since it uses as much as digits as its factorization.

20832257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10158.

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 20832257 is about 4564.2367379443. The cubic root of 20832257 is about 275.1558653605.

The spelling of 20832257 in words is "twenty million, eight hundred thirty-two thousand, two hundred fifty-seven".